Ashwagandha (Withania somnifera)

BACKGROUND: Ashwagandha (Withania somnifera), as an important herbal medicine, has been increasingly recognized for its role in mental health management, particularly in reducing stress and anxiety, and reflects the growing relevance of complementary and alternative medicine in addressing psychological well-being. The present study aims to investigate its effectiveness by pooling the evidence from existing randomized controlled trials (RCTs). METHODS: Major medical databases of PubMed, Scopus, and Web of Science Core Collection were searched. Eligible studies were included. Meta-analysis, meta-regression, non-linear dose-response analysis, and subgroup analyses were conducted. Standardized mean differences (SMDs) were calculated. P-values < 0.05 were considered as statistically significant. The study protocol was registered in the PROSPERO database (CRD420251073134). RESULTS: Twenty-two studies met the eligibility criteria and were included. Meta-analysis revealed that supplementation with ashwagandha significantly improves stress (SMD = -5.88; 95 % CI: -8.15 to -3.60), depression (SMD = -5.68; 95 % CI: -8.43 to -2.94), and anxiety (SMD = -6.87; 95 % CI: -8.77 to -4.97). There was significant linear (coefficient = 0.005, P = 0.031) and non-linear (P-nonlinearity = 0.005) association between dosages of administered ashwagandha and stress levels. CONCLUSION: Current evidence suggests that ashwagandha supplementation holds promising potential in alleviating symptoms of stress, anxiety, and depression. However, to strengthen these findings and translate them into clinical recommendations, well-designed, high-quality trials are still needed to address existing heterogeneity and to establish the most effective dosages and intervention durations.

BackgroundThe global medicine market is projected to reach US$417 billion by 2033, reflecting rising demand for natural healthcare alternatives. Ashwagandha (Withania somnifera) is widely used in Ayurvedic medicine for stress management, but evidence supporting its efficacy remains inconsistent.AimThis systematic review and meta-analysis evaluated Ashwagandha's impact on cortisol levels (a biological stress marker) and perceived stress via Perceived Stress Scale (PSS) scores across randomized controlled trials (RCTs).MethodPRISMA guidelines were followed. Four databases (PubMed, CINAHL, Google Scholar, and Scopus) were searched for studies from January 2012 to February 2024, yielding seven studies on cortisol and six on perceived stress (n = 488 participants). Inclusion criteria were RCTs longer than or equal to two weeks, oral doses ≥250 mg/day, and reporting cortisol and PSS outcomes. The Cochrane Risk of Bias 2 tool was used to assess the risk of bias.ResultsThere was a statistically significant reduction in cortisol levels (-1.16 µg/dL, 95% CI: -1.64 to -0.69, P < 0.001). No significant impact was observed on perceived stress (SMD = -0.355, 95% CI: -1.188 to 0.47; P = 0.40). Heterogeneity was moderate (I2 = 50.9%). However, no statistically significant impact was observed on perceived stress (SMD = -0.355, 95% CI: -1.188 to 0.47; P-value = 0.40). The heterogeneity among studies was moderate (I2 = 50.9%). Risk of bias was generally moderate; most studies reported adequate randomization, but some lacked allocation concealment. No publication bias was detected.ConclusionFindings support Ashwagandha's role in lowering cortisol, but gaps remain regarding long-term safety, dosing, and effectiveness across diverse populations. The disconnect between cortisol and PSS outcomes highlights the need for longer treatment duration and broader demographic inclusion. Longitudinal research is recommended to validate Ashwagandha as a holistic stress management tool.

The purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha (Withania somnifera) on maximum oxygen consumption (VO2max), as well as to provide directions for clinical practice. A systematic search was conducted in three electronic databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). The inclusion criteria were: (a) VO2max data, with means ± standard deviation before and after the supplement intervention, (b) the study was randomized controlled trial (RCT), (c) the article was written in English. The quality of evidence was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A meta-analysis was performed to determine effect sizes. Five studies were selected in the systematic review (162 participants) and four were included in the meta-analysis (142 participants). Results showed a significant enhancement in VO2max in healthy adults and athletes (p = 0.04). The mean difference was 3.00 (95% CI from 0.18 to 5.82) with high heterogeneity. In conclusion, Ashwagandha supplementation might improve the VO2max in athlete and non-athlete people. However, further research is need to confirm this hypothesis since the number of studies is limited and the heterogeneity was high.

Stress and anxiety are interconnected, sharing both behavioural and neural foundations. Ashwagandha (Withania somnifera) helps reduce stress and anxiety. This study aimed to evaluate the efficacy and safety of a proprietary herbal extract of ashwagandha root (APB) in adult men and women with moderate stress and anxiety. This 8-week, randomized, double-blind, three-arm, placebo-controlled trial included 141 healthy men and women aged 18-65 years with stress and anxiety. Participants were randomized to receive either 300 mg of APB twice daily (n = 47), ashwagandha root extract (ARE, n = 47), or placebo (PL, n = 47) for 8 weeks. The primary endpoint was a change in serum cortisol levels at week 8. Secondary endpoints were the mean changes in Perceived Stress Scale (PSS), Hamilton Anxiety Rating Scale (HAM-A), Profile of Mood States (POMS), and Oxford Happiness Questionnaire (OHQ) scores. Safety was assessed through clinical adverse events (AEs) and laboratory parameters. Between-group comparisons were analyzed using one-way ANOVA with Tukey's post-hoc test, and within-group changes were assessed using paired t-tests. At 8 weeks, all groups have shown a significant reduction in serum cortisol, and improvements in PSS (P < 0.0001), HAM-A (P = 0.001), and POMS domain scores (tension, depression, and anger, P < 0.0001). In addition, the APB showed significant differences compared with ARE and PL for PSS, HAM-A total score, OHQ, and POMS (P < 0.05). The proprietary herbal extract of ashwagandha root (300mg twice daily) is considered an effective and safe intervention for reducing stress and anxiety. © 2026 The Author(s).

The relationship between excess body weight and stress significantly impacts overall health. The current study evaluated the efficacy and safety of Ashwagandha (Withania somnifera) root extract (ARE) in altering stress biomarkers and its role in weight management. In this prospective, randomized, double-blind, placebo-controlled study, 100 participants (age: 19-65 years) were randomized to receive either ARE 300 mg twice daily (n = 50) or an identical placebo (PL, n = 50) for 24 weeks. The primary efficacy endpoints were changes in body weight and body mass index (BMI). Secondary endpoints included evaluation of stress (Perceived Stress Scale, PSS), quality of life (Short Form-12 Quality of Life Scale), subjective satisfaction (Subjective Satisfaction Scale, SSS), and food cravings (Food Cravings Questionnaire-Trait, FCQ-T). Clinical safety was assessed based on treatment-emergent adverse events (TEAEs) and laboratory parameters, including complete blood count, renal function tests, liver function tests, lipid profile, thyroid function tests, and glycemic parameters (plasma glucose and glycated hemoglobin). Efficacy was analyzed in 91 patients. ARE administration resulted in a significant reduction in body weight (-8.46 ± 3.86 kg; P < 0.0001) and BMI (-3.31 ± 1.57 kg/m2; P < 0.0001) compared to the PL (-2.41 ± 2.07 kg and -0.93 ± 0.79 kg/m2 for body weight and BMI, respectively). Compared with PL, ARE showed significant improvements (P < 0.05) in PSS, SF-12, SSS, and FCQ-T scores. A total of seven participants with ARE and six with PL reported mild adverse events (nausea, abdominal pain, and drowsiness), which were resolved without any intervention. Ashwagandha root extract may offer a safe and beneficial approach for stress reduction and weight management. © 2025 The Author(s).

BACKGROUND: Mild cognitive impairment (MCI) is a condition in which people have memory or thinking problems than other people of their age. This study evaluated the effectiveness and safety of ashwagandha extract standardized with Sominone (Somin-On™) in enhancing memory and cognitive functioning in adults with MCI. METHODS: In this randomized double-blind, placebo-controlled pilot study, 40 subjects with MCI were randomized in a 1:1 ratio to receive either Somin-On™ (250 mg daily) or a placebo for 60 days. The outcome measures, improvement in memory and other cognitive functions after 30 and 60 days were assessed using Montreal Cognitive Assessment (MoCA); Mini-mental state examination (MMSE); Wechsler Memory Scale-III (WMS-III)); and Shepard mental rotation task. RESULTS: Subjects treated with Somin-On™ showed significant improvements in immediate memory, general memory, working memory and visuospatial processing and the response assessed using WMS-III after 30 and 60 days outperforming the placebo group. Scores on the Shepard Mental Rotation test in Somin-On™ group showed a significant rise by 12.22% at 30 days and 31.67% at 60 days, from baseline. Significant improvement was observed with Somin-On™ in memory assessment scales viz. MoCA (7.83% at 30 days and 14.77% at 60 days, from baseline) and MMSE (9.26% at 30 days and 19.21% at 60 days, from baseline) compared to placebo group. CONCLUSIONS: The supplementation of Somin-On™ is an effective therapy to improve the immediate, general and working memory, as well as cognitive functions like attention and information processing speed in adults with MCI.

Erratum in Eur J Sport Sci. 2025 May;25(5):e12292. doi: 10.1002/ejsc.12292. Ashwagandha is a supplement with the potential to improve exercise performance. However, research on its impact on female athletes remains limited. This study investigates the effects of ashwagandha on exercise recovery and muscle strength in professional female athletes, addressing a gap in understanding its role in this underrepresented population. Female footballers were randomly assigned to a 600 mg/day ashwagandha root extract group (ASH, n = 15; age: 26.0 ± 4.9 years, height: 1.66 ± 0.1 m, body mass: 61.5 ± 7.5 kg, and career: 15.2 ± 7.4 years) or a placebo group (PLA, n = 15; age: 23.5 ± 5.5 years, height: 1.66 ± 0.1 m, body mass: 61.5 ± 6.0 kg, and career: 13.1 ± 4.9 years). Recovery was assessed with total quality recovery (TQR), Hooper Index (HI) and rate of perceived exertion (RPE). Strength was assessed by hand grip, medicine ball throw (MBT), countermovement jump (CMJ) and peak power. Dietary intake was recorded prior to baseline measurements. Repeated measures ANOVA, Bonferroni test, independent t-tests and ANCOVA were used in the analysis. A significant group × time interaction effect was found for TQR (p = 0.026), with the post-hoc analysis revealing a significant difference between ASH and PLA at 28 days (p = 0.039). Perceived sleep quality from HI improved significantly in ASH compared to PLA (p = 0.038), with a significant change at 14 days. The ANCOVA analysis highlighted the significant influence of carbohydrate intake on hand grip strength (p = 0.005), MBT (p < 0.001) and body mass (p < 0.001). A dosage of 600 mg of ashwagandha root extract for 28 days may improve TQR and enhance perceived sleep quality in female footballers. Future research should investigate the optimal dosage and test across a broader range of athletic populations. Trials Registration: The trial is registered on ClinicalTrials.gov with the ID NCT06264986. © 2025 The Author(s). European Journal of Sport Science published by Wiley‐VCH GmbH on behalf of European College of Sport Science.

This prospective, randomized, placebo-controlled study assessed the effects of Ashwagandha root extract (ARE) on cognition, energy, and mood in adults with self-reported cognitive and energy problems. Healthy subjects aged 30-75 years were randomized to receive ashwagandha (Withania somnifera) root extract (ARE) 600 mg/day (n = 60)/identical placebo (n = 60) orally for 8 weeks. Cognitive function was assessed at baseline and week 8 using a Computerized Mental Performance Assessment System (COMPASS). Secondary outcomes were Profile of Mood States Abbreviated Version (POMS-A), Mental Fatigue Scale (MFS) and Behavior Rating Inventory of Executive Function-Adult (BRIEF-A) for effects on mood, mental fatigue and executive function, respectively, assessed at baseline, week 4 and 8. Greater improvement (p < .05) from baseline scores were seen with ARE as against placebo for COMPASS items episodic memory, working memory and accuracy of attention. ARE also improved the POMS-A, MFS and BRIEF-A scores from baseline suggesting an improvement in mood, vigor, and an increase in the executive functioning respectively with ARE. The herb was well tolerated and had a good patient compliance with no serious adverse events reported in either of the groups. This study suggests that a dose of 600 mg a day can improve cognition, energy, and mood in adults with self-reported cognitive and energy problems.

BACKGROUND: Ashwagandha is a well-known Ayurvedic herb used for youthful vigor and wellbeing. This study investigated the effects of 600 mg standardized root extract (>5% withanolides) of Ashwagandha ( Withania somnifera) on muscle size, strength and cardiorespiratory endurance following resistance training. METHODS: In this eight-week, parallel-group, multicenter, randomized, double-blind, placebo-controlled clinical study, 80 healthy male and female participants aged 18-45 years, who engaged in regular physical activity were randomly allocated in a 1:1 ratio to receive Ashwagandha (AG, n=40) 300 mg capsules twice daily for eight weeks, or identical placebo (PB, n=40). Seven (3 AG, 4 PB) participants were excluded due to poor compliance. All participants conducted eight-week resistance training. Study outcomes included muscle strength (1RM bench press and leg extension), muscle size (circumference of arm, chest and upper thigh) and cardio-respiratory endurance (VO 2max) assessed at baseline and at eight weeks. Analysis of covariance (ANCOVA) was used to estimate adjusted differences based on sex, BMI and chest circumference at baseline. RESULTS: AG caused greater improvement in bench press (males: p = 0.0084; females: p = 0.0005), leg press (males: p = 0.0049; females: p = 0.018) and endurance (males: p <0.0001; females: p <0.0001) as compared to PB. Also, greater improvements in muscle girth for arm, chest and thigh were seen in both male and female participants with AG. No adverse events were reported in the study. CONCLUSIONS: Eight weeks of AG root extract supplementation along with resistance training is effective in improving muscle strength, growth and endurance in both male and female participants. AG root extract could be a safer, effective and low-cost alternative for athletes to improve muscle endurance. Copyright: © 2024 Verma N et al.

BACKGROUND: Ashwagandha has been reported to reduce stress and attenuate cognitive decline associated with inflammation and neurodegeneration in clinical populations. However, the effects as a potential nootropic nutrient in younger populations are unclear. This study examined the effects of liposomal ashwagandha supplementation on cognitive function, mood, and markers of health and safety in healthy young men and women. METHODS: 59 men and women (22.7 ± 7 yrs., 74.9 ± 16 kg, 26.2 ± 5 BMI) fasted for 12 h, donated a fasting blood sample, and were administered the COMPASS cognitive function test battery (Word Recall, Word recognition, Choice Reaction Time Task, Picture Recognition, Digit Vigilance Task, Corsi Block test, Stroop test) and profile of mood states (POMS). In a randomized and double-blind manner, participants were administered 225 mg of a placebo (Gum Arabic) or ashwagandha (Withania somnifera) root and leaf extract coated with a liposomal covering. After 60-min, participants repeated cognitive assessments. Participants continued supplementation (225 mg/d) for 30 days and then returned to the lab to repeat the experiment. Data were analyzed using a general linear model (GLM) univariate analysis with repeated measures and pairwise comparisons of mean changes from baseline with 95% confidence intervals (CI). RESULTS: Ashwagandha supplementation improved acute and/or 30-day measures of Word Recall (correct and recalled attempts), Choice Reaction Time (targets identified), Picture Recognition ("yes" correct responses, correct and overall reaction time), Digit Vigilance (correct reaction time), Stroop Color-Word (congruent words identified, reaction time), and POMS (tension and fatigue) from baseline more consistently with several differences observed between groups. CONCLUSION: Results support contentions that ashwagandha supplementation (225 mg) may improve some measures of memory, attention, vigilance, attention, and executive function while decreasing perceptions of tension and fatigue in younger healthy individuals. Retrospectively registered clinical trial ISRCTN58680760.

BACKGROUND: Stress is a state of homeostasis in the body being challenged, resulting in a systemic response. It has become more prevalent in recent years and affects mental and physical health. AIMS: Evaluate the effects of ashwagandha on stress, fatigue, and sex hormones in overweight or mildly obese men and women with self-reported stress and fatigue. METHODS: Two-arm, parallel-group, 12-week, randomized, double-blind, placebo-controlled trial on overweight or mildly obese men and women aged 40-75 years, supplementing with 200 mg of an ashwagandha root extract (Witholytin®) twice daily. RESULTS/OUTCOMES: Supplementation with ashwagandha was associated with a significant reduction in stress levels based on the Perceived Stress Scale (primary outcome); however, the improvements were not significantly different to the placebo group (p = 0.867). Based on the Chalder Fatigue Scale, there was a statistically significant reduction in fatigue symptoms in the ashwagandha group compared to the placebo group (p = 0.016), and participants taking ashwagandha also experienced a significant increase in heart rate variability (p = 0.003). However, there were no significant between-group differences in other self-report outcome measures. In the men taking ashwagandha, there was a significant increase in the blood concentrations of free testosterone (p = 0.048) and luteinizing hormone (p = 0.002) compared to the placebo group. CONCLUSIONS/INTERPRETATION: The results of this study suggest that in overweight middle-to-older age adults experiencing high stress and fatigue, compared to the placebo, ashwagandha did not have a significantly greater impact on perceived stress levels. However, based on secondary outcome measures, it may have anti-fatigue effects. This may be via its impact on the autonomic nervous system. However, further research is required to expand on these current findings.

BACKGROUND: Ayurveda interventions have been used for prophylaxis and care during the COVID-19 pandemic in India and have shown promising results in promoting early clinical recovery from COVID-19. OBJECTIVE: To assess the efficacy and safety of Ashwagandha [Withania somnifera (L.) Dunal] tablet and Shunthi (Zingiber officinale Roscoe) capsule in mild and moderate COVID-19 compared to conventional standard care. METHODS: A randomized controlled exploratory trial was conducted at a designated COVID-19 care center in India with 60 participants having mild or moderate COVID-19. Ashwagandha, two tablets (250 mg each), and Shunthi, two capsules (500 mg each) twice daily for 15 days, were given orally to the participants in the Ayurveda group (AG) and the control group (CG) received conventional standard care. The outcome measures included clinical recovery rate, the proportion of participants with negative RT-PCR assay for COVID-19 on day 7 and day 15, mean time to attain clinical recovery, change in pro-inflammatory markers, serum IgG for COVID-19, HRCT chest findings, disease progression and incidence of adverse events (AE). RESULTS: A total of 60 participants were enrolled, and the data of 48 participants (AG = 25 and CG = 23) were considered for the statistical analysis. The mean time for clinical recovery was reduced by almost 50 % in the AG (6.9 days) compared to CG (13.0 days) (p < 0.001). The proportion of participants who attained viral clearance in AG was 76.0 % compared to 60.8 % in the CG (RR= 1.24, 95 % CI: 0.841, 1.851, p-value = 0.270). Changes in the pro-inflammatory markers, serum IgG for COVID-19, and HRCT chest findings were comparable in both groups, and no AE or disease progression was reported. CONCLUSIONS: The Ayurveda interventions, Ashwagandha and Shunthi, can effectively reduce the duration of clinical recovery and improve time for viral clearance in mild and moderate COVID-19. These interventions were observed to be safe and well-tolerated during the duration of the trial. TRIAL REGISTRATION: Clinical Trial Registry of India - CTRI/2020/08/027224.

BACKGROUND: Perimenopause is the period during which many physiological changes mark the transition into the final menstrual period of a woman and these changes are associated with climacteric symptoms. OBJECTIVES: This study aimed to assess the efficacy and tolerability of an Ashwagandha root extract on the climacteric symptoms, quality of life (QoL), and hormonal parameters in perimenopausal women. MATERIALS AND METHODS: In this 8-week, randomized, double-blind, placebo-controlled study, 100 women with climacteric symptoms were randomly allocated to take either a placebo or 300 mg of an Ashwagandha root extract twice daily. Outcomes were measured using the menopause rating scale (MRS), menopause-specific QoL (MENQoL), hot flash score, and hormonal changes in estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. RESULTS: Among 100 participants enrolled, 91 participants completed the study. In comparison with the placebo, ashwagandha supplementation was associated with a statistically significant reduction in total MRS score (p < 0.0001), reflected by significant reductions in the psychological (p = 0.0003), somato-vegetative (p = 0.0152), and urogenital (p < 0.0001) domains. Ashwagandha intake demonstrated a statistically significant reduction in total MENQoL scores (p < 0.0001) and was also associated with a statistically significant increase in serum estradiol (p < 0.0001) and a significant reduction in serum FSH (p < 0.0001) and serum LH (p < 0.05) compared with the placebo. There was no significant between the group differences in the serum testosterone level. CONCLUSION: These findings suggest that ashwagandha root extract can be a safe and effective option to relieve mild to moderate climacteric symptoms during perimenopause in women. © 2021 Japan Society of Obstetrics and Gynecology.

Ashwagandha (Withania somnifera [L] Dunal) is emerging as one of the top 10 botanicals in the market due to its claimed health benefits as an adaptogen. Alongside its popularity, the lack of standardization in botanical dietary supplements and potential interactions with prescription drugs raise safety concerns. This study aimed to investigate the potential of ashwagandha extracts to induce cytochrome P450 (P450) enzymes, which are critical for drug metabolism and implicated in botanical-drug interactions. A sandwich-cultured in vitro assay using primary human hepatocytes was utilized to evaluate the induction potential of aqueous and 70% ethanolic extracts of ashwagandha roots and leaves on CYP3A4, CYP2B6, and CYP1A2-enzymes commonly involved in drug metabolism. Unlike prior studies that focused on root extracts or used HepG2 cell lines, this research included both root and leaf plant extracts, with the latter being assessed for the first time. Our approach using primary hepatocytes enhances clinical relevance compared to other in vitro models (such as HepG2 cell lines). Additionally, cytotoxicity was examined using CellTitre-Glo Luminescent Assay, measuring cell viability at three different incubation times (24, 48, and 72 hours) to assess the potential cytotoxic effect of the ashwagandha plant extracts. Our findings revealed that 70% ethanol ashwagandha root extracts (WSR-2) modulated CYP3A4 enzyme expression and activity. Preliminary studies on cytotoxicity indicated dose- and time-dependent impact on hepatocyte viability with a high concentration of 70% ethanol ashwagandha leaf extracts (WSL-2). The study highlights the importance of understanding ashwagandha's impact on P450-based drug metabolism and its safe co-administration with prescribed drugs. Clinical evidence for the adaptogenic effects of Withania somnifera and Rhodiola rosea - A systematic review with molecular interpretation of psychometric outcomes. Łuszczak J(1), Kocki J(2). Author information: (1)Department of Biology with Genetics, Medical University, Lublin, Poland. (2)Department of Clinical Genetics, Medical University, Lublin, Poland. INTRODUCTION AND OBJECTIVE: Adaptogens are plant-d

15. Ann Agric Environ Med. 2026 Mar 25;33(1):3-11. doi: 10.26444/aaem/213417. Epub 2025 Dec 9. Clinical evidence for the adaptogenic effects of Withania somnifera and Rhodiola rosea - A systematic review with molecular interpretation of psychometric outcomes. Łuszczak J(1), Kocki J(2). Author

BACKGROUND: Ashwagandha (Withania somnifera) is an adaptogenic herb used to prevent and treat psychosomatic disorders. This systematic review and meta-analysis evaluated the effects and safety of Ashwagandha on psychosomatic functions related to stress and anxiety among patients. METHODS: A comprehensive search was conducted in MEDLINE, EMBASE, PubMed, PsychINFO, and the Cochrane Library for articles published from January 2000 to January 2022. Randomized controlled trials that examined the effects of Ashwagandha on stress and anxiety were included. Two authors independently extracted all relevant data from the included studies. Both subjective and objective measures of stress and anxiety were assessed as outcome variables. RESULT: Nine randomized controlled trials involving 558 patients were eligible for this study. The findings of the meta-analysis showed a significant effect of Ashwagandha formulations on the Perceived Stress Scale (PSS) (MD = -4.72, 95 % CI = [-8.45 to -0.99]), Hamilton Anxiety Scale (HAS) (MD = -2.19, 95 % CI = [-3.83 to -0.55]), and serum cortisol levels (MD = -2.58, 95 % CI = [-4.99 to -0.16]) compared to the placebo group. Among the included studies, four reported mild to moderate adverse events. CONCLUSION: The findings from the included studies indicate that Ashwagandha formulations have beneficial effects on stress and anxiety. The adverse effects associated with Ashwagandha are limited; however, further information is required to determine its safety with long-term administration.

OBJECTIVE: To determine the effect of Ashwagandha extract on sleep. METHODS: A comprehensive search was conducted in CENTRAL, MEDLINE, SCOPUS, Google Scholars, World Health Organization Trials Portal, ClinicalTrials.gov, Clinical Trial Registry of India, and AYUSH Research Portal for all appropriate trials. Randomized controlled trials that examined the effect of Ashwagandha extract versus placebo on sleep in human participants 18 years old and above were considered. Two authors independently read all trials and independently extracted all relevant data. The primary outcomes were sleep quantity and sleep quality. The secondary outcomes were mental alertness on rising, anxiety level, and quality of life. RESULTS: A total of five randomized controlled trials containing 400 participants were analyzed. Ashwagandha extract exhibited a small but significant effect on overall sleep (Standardized Mean Difference -0.59; 95% Confidence Interval -0.75 to -0.42; I2 = 62%). The effects on sleep were more prominent in the subgroup of adults diagnosed with insomnia, treatment dosage ≥600 mg/day, and treatment duration ≥8 weeks. Ashwagandha extract was also found to improve mental alertness on rising and anxiety level, but no significant effect on quality of life. No serious side effects were reported. CONCLUSION: Ashwagandha extract appears to has a beneficial effect in improving sleep in adults. However, data on the serious adverse effects of Ashwagandha extract are limited, and more safety data would be needed to assess whether it would be safe for long-term use.

OBJECTIVE: To assess existing reported human trials of Withania somnifera (WS; common name, ashwagandha) for the treatment of anxiety. DESIGN: Systematic review of the literature, with searches conducted in PubMed, SCOPUS, CINAHL, and Google Scholar by a medical librarian. Additionally, the reference lists of studies identified in these databases were searched by a research assistant, and queries were conducted in the AYUSH Research Portal. Search terms included "ashwagandha," "Withania somnifera," and terms related to anxiety and stress. Inclusion criteria were human randomized controlled trials with a treatment arm that included WS as a remedy for anxiety or stress. The study team members applied inclusion criteria while screening the records by abstract review. INTERVENTION: Treatment with any regimen of WS. OUTCOME MEASURES: Number and results of studies identified in the review. RESULTS: Sixty-two abstracts were screened; five human trials met inclusion criteria. Three studies compared several dosage levels of WS extract with placebos using versions of the Hamilton Anxiety Scale, with two demonstrating significant benefit of WS versus placebo, and the third demonstrating beneficial effects that approached but did not achieve significance (p=0.05). A fourth study compared naturopathic care with WS versus psychotherapy by using Beck Anxiety Inventory (BAI) scores as an outcome; BAI scores decreased by 56.5% in the WS group and decreased 30.5% for psychotherapy (p<0.0001). A fifth study measured changes in Perceived Stress Scale (PSS) scores in WS group versus placebo; there was a 44.0% reduction in PSS scores in the WS group and a 5.5% reduction in the placebo group (p<0.0001). All studies exhibited unclear or high risk of bias, and heterogenous design and reporting prevented the possibility of meta-analysis. CONCLUSIONS: All five studies concluded that WS intervention resulted in greater score improvements (significantly in most cases) than placebo in outcomes on anxiety or stress scales. Current evidence should be received with caution because of an assortment of study methods and cases of potential bias.